According to Nigel at The Hub, both Protoforms have turned up at Toys 'R' Us in Cardiff. http://www.websitetoolbox.com/tool/post/thehub/vpost?id=1489767&trail=324 So there we have it, the movie merchandising blitz seems to have now started in the UK! Sort of.
Yeah, I already have them too, but it's good that fans at large can pick up these underated toys that don't look in the least bit like rocks. They're listed on the web site, but are "out of stock" right now (which means they're not yet in stock!) http://www.toysrus.co.uk/Product.aspx/TruHome/TruToys/TruToysActionFigures/TruToysActionFiguresTransformers/379018
Protoforms are out in Germany too. We've already had some reports and I personally saw LOADS of them in a local TRU store today.
Picked up both of them from Solihull TRU this evening. They had two pegs full. Quite nice overall. If you're only going to get one of them though, I'd say Prime is the better of the two.
I saw them in TRU Chatham this evening, several pegs of them. The Chatham store is very well stocked in general for TF fans.